Static friction is a self-adjusting force.

• If you apply a small force $F$, static friction $f_s$ exactly matches it ($f_s=F$) to keep the body at rest.
• As you increase $F$, $f_s$ also increases to match it, but only up to a point.
• This point is the limiting friction $f_{max}={\mu }_{s}N$.
• Once the applied force exceeds $f_{max}$, the body slips, and we switch to kinetic friction. Static friction is always $\le {\mu }_{s}N$.